{"id":"F2006B08544","name":"AD/CHA/18 - Airspeed Restriction - Front Wing Strut","slug":"ad-cha-18-airspeed-restriction-front-wing-strut","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51329,"registerId":"commonwealth-F2006B08544-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CHA/18 - Airspeed Restriction - Front Wing Strut","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  American Champion (Aeronca, Bellanca) Series Aeroplanes\n\n \n\nAD/CHA/18 Airspeed Restriction - Front Wing Strut 1/78\n\nApplicability: Model 7ECA S/Nos. 1 to 722, 725, 723-70 to 1238-78. All model 7GC; All model\n\n7GCA; Model 7GCAA S/Nos. 1 to 198, 200 to 204, 276, 205-70 to 355-78; All\n\nmodel 7GCB; Model 7GCBC with S/Nos. 1 to 201, 205, 207, 202-70 to 1024-78; All\n\nmodel 7HC; Model 7KCAB S/Nos. 1 to 208, 210 to 226, 270, 271, 209-70 to 617-77\n\nexcept those with front wing struts Bellanca P/N 5-392.\n\n \n\nRequirement: Action in accordance with Bellanca SL No. C-127.\n\n \n\nNote: FAA AD 77-20-05, Amendment 39-3069 refers.\n\n \n\nCompliance: In accordance with Requirement Document.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific structural defect in a defined aircraft population. It has not expanded beyond its original purpose of mitigating front wing strut failure risk."},"complexity_factors":["Single operational requirement (airspeed restriction) with clear applicability","Serial number-based applicability list is lengthy but mechanically straightforward","Single cross-reference to manufacturer service letter (Bellanca SL No. C-127)","Single exception clause (Bellanca P/N 5-392 struts)","No nested conditional logic or defined terms section","Extremely short document (approximately 150 words of substantive content)"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998.\n\n**What it does:** It imposes a speed limit (airspeed restriction) on specific American Champion aeroplanes (formerly made by Aeronca and Bellanca) due to a safety issue with the front wing strut.\n\n**Who it affects:** Owners and operators of specific models of American Champion aircraft, including:\n- Model 7ECA (specific serial numbers)\n- All Model 7GC, 7GCA, 7GCB, and 7HC aircraft\n- Specific serial numbers of Models 7GCAA, 7GCBC, and 7KCAB\n\n**Important exception:** Aircraft that have already been fitted with Bellanca part number 5-392 front wing struts are **exempt** from this directive.\n\n**What must be done:** Operators must follow the instructions in Bellanca Service Letter No. C-127. This is a manufacturer's technical document that details the required inspection, modification, or operational limitation.\n\n**Why it matters:** Wing struts are critical structural components. A failure could lead to wing collapse and catastrophic accident. This AD ensures potentially defective struts are identified and addressed before they cause harm.\n\n**International link:** The note references a US Federal Aviation Administration (FAA) directive (AD 77-20-05), showing this safety issue was also recognised in the United States."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument defines a specific scope of affected aircraft and mandates action by reference to Bellanca SL No. C-127 and a Requirement Document (\"Applicability\", \"Requirement\", \"Compliance\"). There is no indication within the text provided that the scope has been changed from an earlier intent; the directive as written limits its scope to the listed models and serial numbers and delegates technical detail to the referenced documents."},"complexity_factors":["Narrow, technical applicability tied to specific models and serial numbers (\"Applicability\").","Substantive details are delegated to an external service letter (Bellanca SL No. C-127) rather than contained in the directive itself (\"Requirement\").","Compliance is stated only by reference to a Requirement Document; the directive does not include procedures, timescales or costs (\"Compliance\").","Cross-reference to an FAA AD (\"Note\") requires checking another regulator's document for related context.","Brevity of the directive increases reliance on multiple external documents to understand obligations and implementation."],"plain_english_summary":"What this instrument changes mechanically:\n\n- It applies to a defined set of American Champion (Aeronca, Bellanca) Model 7 series aeroplanes by model and serial number (see \"Applicability\").\n- It requires the actions set out in Bellanca Service Letter No. C-127 (see \"Requirement: Action in accordance with Bellanca SL No. C-127\").\n- It requires compliance in accordance with the referenced Requirement Document (see \"Compliance: In accordance with Requirement Document\").\n- The document is published as an Airworthiness Directive under the Civil Aviation Regulations and is listed in the Schedule of Airworthiness Directives (header).\n\nWho is affected and who decides:\n\n- The directive applies to the aircraft listed under \"Applicability\". The instrument is issued under the Civil Aviation Safety Authority framework (header). The specific actions to be taken are those set out in Bellanca SL No. C-127 (\"Requirement\").\n\nStated purpose and how that is implemented:\n\n- The title of the instrument indicates an airspeed restriction related to the front wing strut (title: \"AD/CHA/18 Airspeed Restriction - Front Wing Strut\"). The directive implements that purpose by mandating compliance with the external service letter (\"Requirement: Action in accordance with Bellanca SL No. C-127\").\n\nCosts, incentives and compliance mechanics (source-grounded):\n\n- The directive creates an obligation to carry out the actions described in Bellanca SL No. C-127 (\"Requirement\"), and to comply as specified in the Requirement Document (\"Compliance\"). The directive therefore places the operational burden of carrying out those actions on the owner/operator of each aircraft to which the \"Applicability\" applies, because the aircraft are the objects of the requirement (\"Applicability\").\n- The text does not specify the nature, duration or monetary cost of the required actions; those details are contained in Bellanca SL No. C-127 and the Requirement Document (\"Requirement\"; \"Compliance\").\n\nTrade-offs and implementation risk (source-grounded):\n\n- The directive is brief and depends on an external manufacturer service letter and a Requirement Document for substantive detail (\"Requirement\"; \"Compliance\"). That dependence means the practical effect and the resources required to comply cannot be determined from this instrument alone.\n- The directive cross-refers to an FAA airworthiness directive (\"Note: FAA AD 77-20-05, Amendment 39-3069 refers\"), indicating related regulatory material exists beyond this document.\n\nConcrete obligations and decision points:\n\n- The concrete obligation set by this instrument is: perform the actions in Bellanca SL No. C-127 on the aircraft listed under \"Applicability\" and comply in accordance with the Requirement Document (\"Requirement\"; \"Compliance\").\n- The instrument does not itself set technical limits, procedures, or timelines in the text provided; those are delegated to the referenced documents (\"Requirement\"; \"Compliance\")."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cha-18-airspeed-restriction-front-wing-strut","history":"/api/acts/ad-cha-18-airspeed-restriction-front-wing-strut/history","analysis":"/api/acts/ad-cha-18-airspeed-restriction-front-wing-strut/analysis","conflicts":"/api/acts/ad-cha-18-airspeed-restriction-front-wing-strut/conflicts","importantCases":"/api/acts/ad-cha-18-airspeed-restriction-front-wing-strut/important-cases","documents":"/api/acts/ad-cha-18-airspeed-restriction-front-wing-strut/documents"}}